Table 1 Patient characteristics and outcomes

Sex, male

1672 (73%)

5914 (69%)***

1823 (53%)***

12,147 (61%)***

10,373 (58%)***

BMI, kg/m²

27.8 [25.4—31.2]

29.2 [26.1—33.0]***

25.7 [22.6—29.7]***

25.2 [22.4—29.1]***

26.2 [23.2—30.3]***

 Normal (< 25)

490 (21%)

1487 (17%)***

1516 (44%)***

9262 (46%)***

7037 (39%)***

 Overweight (25 to < 30)

1032 (45%)

3281 (38%)***

1012 (29%)***

5957 (30%)***

5699 (32%)***

 Obese Class 1: (30 to < 35)

481 (21%)

2261 (26%)***

464 (13%)***

2406 (12%)***

2631 (15%)***

 Class 2: (35 to < 40)

161 (7%)

951 (11%)***

203 (6%)

947 (5%)***

1082 (6%)

 Class 3: (> 40)

89 (4%)

508 (6%)***

148 (4%)

636 (3%)

821 (5%)

Age, years

65 [56—72]

64 [55—71]*

66 [57—74]***

69 [60—77]***

69 [59—77]***

APACHE IV score

58 [47—71]

59 [49—71]

64 [51—80]***

73 [58—91]***

78 [62—98]***

APACHE IV APS^a score

46 [38—57]

48 [40—58]*

50 [39—65]***

57 [44—74]***

62 [47—81]***

Aids

1 (0%)

7 (0%)

6 (0%)

87 (0%)*

42 (0%)

Cardiovascular insuffiency

23 (1%)

117 (1%)

115 (3%)***

877 (4%)***

754 (4%)***

Chronic dialysis

3 (0%)

53 (1%)*

33 (1%)***

244 (1%)***

471 (3%)***

Chronic renal insuffiency

60 (3%)

377 (4%)***

237 (7%)***

1769 (9%)***

2389 (13%)***

Cirrhosis

3 (0%)

40 (0%)

22 (1%)*

286 (1%)***

542 (3%)***

COPD

183 (8%)

809 (9%)

1551 (45%)***

6605 (33%)***

2248 (13%)***

Diabetes mellitus

435 (19%)

2050 (24%)***

693 (20%)

4186 (21%)

4696 (26%)***

Hematological malignancy

35 (2%)

138 (2%)

180 (5%)***

1030 (5%)***

995 (6%)***

Immunological insufficiency

167 (7%)

776 (9%)*

640 (18%)***

3683 (18%)***

3467 (19%)***

Metastatic neoplasm

16 (1%)

55 (1%)

68 (2%)***

1054 (5%)***

1280 (7%)***

Respiratory insufficiency

92 (4%)

361 (4%)

594 (17%)***

2336 (12%)***

581 (3%)

Comorbidity index^b

0.44 (0.014)

0.55 (0.008)***

0.88 (0.014)***

0.84 (0.006)***

0.70 (0.007)***

Mechanical ventilation

1848 (81%)

5030 (59%)***

2449 (71%)***

11,321 (57%)***

5323 (30%)***

PaO2 (mmHg)

77 (66—94)

70 (60—83)***

74 (64—89)***

75 (64—90)***

82 (70—99)***

PaO₂/FiO₂ ratio

125 [90—173]

90 [69—124]***

167 [112—233]***

149 [98—221]***

257 [164—344]***

 No ARDS (> 300 mmHg)

100 (4%)

176 (2%)***

316 (9%)***

1657 (8%)***

5352 (30%)***

 Mild ARDS (> 200–≤ 300 mmHg)

238 (10%)

372 (4%)***

792 (23%)***

3617 (18%)***

4053 (23%)***

 Moderate ARDS (> 100–≤ 200 mmHg)

1058 (46%)

2575 (30%)***

1315 (38%)***

7216 (36%)***

3647 (20%)***

 Severe ARDS (≤ 100 mmHg)

684 (30%)

4645 (54%)***

623 (18%)***

4512 (23%)***

1366 (8%)***

PaCO₂, mmHg

41 [35—48]

36 [32—43]***

47 [37—60]***

41 [33—52]

34 [29—40]***

Respiratory rate (max), breaths/min

31 [26—38]

33 [28—39]***

32 [27—39]***

32 [27—38]***

30 [25—35]***

Vasoactive medication

1569 (69%)

3945 (46%)***

1541 (45%)***

9872 (49%)***

12,140 (68%)

Hematocrit (min)

0.37 [0.34—0.39]

0.38 [0.35—0.41]***

0.37 [0.32—0.41]

0.34 [0.29—0.38]***

0.31 [0.27—0.35]***

Heart rate (max), beats/min

103 [91—116]

98 [87—112]***

116 [101—132]***

118 [102—135]***

116 [100—135]***

Mean arterial pressure (min), mmHg

62 [57—68]

66 [59—73]***

61 [54—69]**

59 [52—67]***

55 [48—62]***

Mean arterial pressure (max), mmHg

107 [97—121]

108 [98—121]

106 [94—121]**

100 [89—114]***

94 [84—106]***

Acute renal failure

204 (9%)

493 (6%)***

402 (12%)**

3650 (18%)***

6283 (35%)***

Creatinine, max, µmol/L

78 [63—102]

73 [60—98]**

84 [60—127]***

97 [67—156]***

146 [93—237]***

Blood urea nitrogen, mg/dL

18 [13—25]

23 [17—31]***

23 [15—35]***

28 [18—43]***

35 [22—54]***

Urinary output, L

1.20 [0.82—1.72]

1.60 [1.19—2.20]***

1.53 [1.00—2.23]***

1.48 [0.92—2.23]***

1.35 [0.66—2.20]***

Bilirubin, µmol/L

9 [6—12]

8 [6—12]***

8 [5—12]***

10 [6—16]***

14 [8—27]***

Sodium, max, mmol/L

138 [136—141]

139 [137—141]***

139 [136—142]***

139 [136—142]***

139 [136—142]***

Potassium (max), mmol/L

4.1 [3.8—4.4]

4.3 [4.0—4.6]***

4.4 [4.0—4.8]***

4.3 [4.0—4.8]***

4.3 [4.0—4.9]***

Glucose (max), mmol/L

8.4 [7.1—10.9]

11.5 [9.2—15.2]***

9.9 [7.9—12.5]***

9.5 [7.5—12.5]***

9.0 [7.1—12.1]***

pH (min)

7.39 [7.32—7.45]

7.44 [7.38—7.48]***

7.36 [7.29—7.43]***

7.38 [7.29—7.44]***

7.38 [7.30—7.44]***

Bicarbonate (max), mmol/L

26 [24—28]

26 [24—28]

28 [24—32]***

25 [22—29]***

22 [19—24]***

Albumin (min), g/L

26 [23—30]

28 [25—32]***

29 [25—34]***

26 [22—31]

24 [20—28]***

White blood cell count (max), × 10⁹/L

9.1 [6.9—12.0]

9.9 [7.2—13.2]***

11.0 [7.5—15.3]***

13.8 [9.4—19.6]***

15.9 [10.2—23.4]***

Thrombocytes (min), × 10⁹/L

228 [172—296]

240 [185—305]***

198 [143—261]***

208 [148—285]***

169 [104—254]***

Temperature, °C

38.7 [38.0—39.4]

37.5 [37.0—38.2]***

38.1 [37.4—38.8]***

38.0 [37.4—38.8]***

38.0 [37.3—38.9]***

Outcome parameters

ICU length-of-stay survivors, days

15 [9—29]

8 [4—17]***

4 [2—8]***

3 [2—7]***

2 [1–5]***

ICU length-of-stay non-survivors, days

11 [5—21]

16 [8—25]***

6 [2—12]***

3 [1—8]***

2 [1–5]***

ICU mortality

609 (27%)

1965 (23%)***

583 (17%)***

3831 (19%)***

3250 (18%)***

Hospital length-of-stay survivors, days

29 [18—45]

19 [12—33]***

11 [7—20]***

13 [8—22]***

13 [7—24]***

Hospital length-of-stay non-survivors, days

15 [8—24]

20 [12—30]***

9 [4—17]***

8 [3—16]***

7 [2—17]***

In-hospital mortality

666 (29%)

2181 (25%)**

755 (22%)***

5257 (26%)*

4456 (25%)***

28-day in-hospital mortality

554 (24%)

1588 (18%)***

676 (20%)***

4705 (24%)

3932 (22%)

90-day in-hospital mortality

664 (29%)

2168 (25%)**

753 (22%)***

5228 (26%)*

4407 (25%)***